Add annotated steps for dart_services

tools/utils.py

 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 # This file contains a set of utilities functions used by other Python-based
 # scripts.
 
 import commands
 import os
 import platform
@@ skipping 254 matching lines @@
 
 def GetBuildDir(host_os):
   return BUILD_ROOT[host_os]
 
 def GetBuildRoot(host_os, mode=None, arch=None, target_os=None):
   build_root = GetBuildDir(host_os)
   if mode:
     build_root = os.path.join(build_root, GetBuildConf(mode, arch, target_os))
   return build_root
 
+def GetBuildSdkBin(host_os, mode=None, arch=None, target_os=None):
+  build_root = GetBuildRoot(host_os, mode, arch, target_os)
+  return os.path.join(build_root, 'dart-sdk', 'bin')
+
 def GetBaseDir():
   return BASE_DIR
 
 def GetShortVersion():
   version = ReadVersionFile()
   return ('%s.%s.%s.%s.%s' % (
       version.major, version.minor, version.patch, version.prerelease,
       version.prerelease_patch))
 
 def GetSemanticSDKVersion(ignore_svn_revision=False):
@@ skipping 312 matching lines @@
     os.chdir(self._working_directory)
 
   def __exit__(self, *_):
     print "Enter directory = ", self._old_cwd
     os.chdir(self._old_cwd)
 
 
 if __name__ == "__main__":
   import sys
   Main()